Antibacterial and antifungal composition

ABSTRACT

An antibacterial and antifungal composition comprising (A) at least one member selected from the group consisting of dehydroacetic acid, sorbic acid and their alkali metal salts and (B) at least one member selected from the group consisting of alkyldi(aminoethyl)-glycines having C 8  to C 16  alkyl groups and their salts, 2-pyridinethiol 1-oxide and its salts, and tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione. The antibacterial and antifungal effects can be synergistically increased when the component (A) is employed in combination with the component (B).

BACKGROUND OF THE INVENTION

The present invention relates to a composition useful as antibacterialand antifungal agent, and more particularly to a composition mainlycontaining dehydroacetic acid, sorbic acid or their alkali metal salts.

It is well known that dehydroacetic acid, sorbic acid and their alkalimetal salts are useful as antibacterial and antifungal agents. Thetoxicity of these antibacterial and antifungal agents is so low thattheir addition to foods is permitted, and they are agents of very highsafety. Therefore, if these agents are usable in any fields such asgeneral industrial products and agricultural products, to say nothing offoods, the usefulness of these agents becomes very great. However, theantibacterial and antifungal effects thereof are not always satisfactoryin the application to industrial products such as paints, sizing agentsand adhesives.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided anantibacterial and antifungal composition comprising (A) at least onemember selected from the group consisting of dehydroacetic acid, sorbicacid and their alkali metal salts and (B) at least one member selectedfrom the group consisting of alkyldi(aminoethyl)glycines having thefollowing general formula:

    R--(NHC.sub.2 H.sub.4).sub.2 --NHCH.sub.2 COOH

wherein R is an alkyl group having 8 to 16 carbon atoms, their salts,2-pyridinethiol 1-oxide and its salts, andtetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione.

The synergistic effect on the antibacterial and antifungal properties isvery remarkable, when the component (A) is employed in combination withthe component (B), and the composition of the invention can be availablyemployed as antibacterial and antifungal agents in various industrialproducts and agricultural products.

DETAILED DESCRIPTION

There are employed, as the component (A) of the composition of theinvention, dehydroacetic acid, sorbic acid and their alkali metal saltssuch as sodium dehydroacetate, potassium dehydroacetate, sodium sorbateand potassium sorbate. These compounds may be employed alone or inadmixture thereof.

In the present invention, the component (A) is employed in combinationwith component (B) selected from the group consisting of higheralkyl-di(aminoethyl)glycines, their salts, 2-pyridinethiol 1-oxide andits salts, and tetrahydro-3,5-dimethyl-2H-1,3,5,-thiadiazine-2-thione.

The higher alkyl-di(aminoethyl)glycines employed in the presentinvention are compounds having the following general formula:

    R--(NHC.sub.2 H.sub.4).sub.2 --NHCH.sub.2 COOH

wherein R is an alkyl group having 8 to 16 carbon atoms. Examples ofthese alkyldi(aminoethyl)glycines are octyl-, nonyl-, decyl-, undecyl-,dodecyl-, tridecyl-, tetradecyl-, pentadecyl- andhexadecyl-di(aminoethyl)glycines, and dodecyl-, tridecyl- andtetradecyl-di(aminoethyl)glycines are preferably employed. Thealkyldi(aminoethyl)glycines are also employed in the form of their saltswith organic or inorganic acids such as hydrochloric acid, sulfuric acidand acetic acid.

2-Pyridinethiol 1-oxide employed as the component (B) is a compoundshown by the following formula: ##STR1## There are also employed in theinvention metal salts of 2-pyridinethiol 1-oxide such as the sodium saltand the zinc salt, shown by the following formulas: ##STR2##

Tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione employed as thecomponent (B) is a compound shown by the following formula: ##STR3##

The components (A) and (B) may be employed in any proportions. Ingeneral, it is desirable to employ the component (B) in an amount of0.5% to 40% by weight based on the total weight of the composition,since the particularly remarkable synergistic effect can be obtained. Asstated before, the feature of the present invention is that theantibacterial and antifungal effects of dehydroacetic acid, sorbic acidor their alkali metal salts can be remarkably increased by thecombination use with a slight amount of the component (B). Although thecompounds employed as the component (B) are known as antibacterial andantifungal agents, it has now been found that synergistic antibacterialand antifungal effect unexpected from a single use of various knownantibacterial and antifungal agents can be obtained, when among knownantibacterial and antifungal agents the component (A) and the component(B) are particularly combined. When the content of the component (B) isless than 0.5% by weight, sufficient synergistic effect cannot beobtained. Also, even if the component (B) is employed in an amount ofmore than 40% by weight, the synergitic effect is not increased.Further, the compounds employed as the component (B) are relativelyexpensive and also the toxicity is higher than the component (A) and,therefore, the use of the component (B) in an amount of more than 40% byweight not only be uneconomical, but also may impair the low toxicitywhich is the feature of the composition of the present invention.

The adding amount of the composition varies depending on the kind of theproducts to be added. In general, sufficient antibacterial andantifungal effects can be obtained in an amount of 50 to 8,000 p.p.m.

Auxiliary agents such as other bactericides, other fungicides, surfaceactive agents and perfumes may be incorporated in the composition of theinvention, as occasion demands.

The composition of the present invention is applicable to any industrialproducts and agricultural products which require the annihilation or theprevention of propagation of bacteria and fungi, such as paints, sizingagents, petroleum products, plastic moldings, fibers, leathers, woods,paper goods, cosmetics, pharmaceuticals, medical appliances, industrialequipments, building material (putties, fiber boards, particle boards,gypsum boards), fruits, grains and vegetables.

The present invention is more particularly described and explained bymeans of the following Examples, in which all % are by weight unlessotherwise noted.

EXAMPLE 1

A liquid culture medium of pH 7.0 containing 1% of peptone, 1% of meatextract and 0.1% of sodium chloride was prepared and sterilized, and 10ml. portions thereof were poured into L-shaped tubes. After adding aprescribed amount of an antibacterial, antifungal composition consistingof the components (A) and (B) as shown in Table 1 to each tube, 0.1 ml.(number of cells: 5×10⁴ cells/ml.) of an aqueous suspension of bacteriaas shown in Table 1 was added to each tube. The thus prepared cultureliquor contained 5×10² cells per milliliter. The culture was carried outat 37° C. for 48 hours with reciprocal shaking, and the state of thegrowth of bacteria was then observed by measuring the number of cells in1 ml. of the culture liquor.

The results are shown in Table 1

                                      TABLE 1                                     __________________________________________________________________________                                         Amount of                                       Antibacterial, antifungal composition                                                                       composition                                                                         Number of                                                         (A)/(B)                                                                             added cells                              Bacteria                                                                             Component (A)                                                                             Component (B)                                                                             by weight                                                                           (p.p.m.)                                                                            (cells/ml.)                        __________________________________________________________________________    Bacillus                                                                             Sodium dehydroacetate                                                                     Dodecyldi (aminoethyl)-                                    subtilis           glycine     95/5  500   5 × 10                                                      95/5  1000  0                                                                 90/10 500   4 × 10                                                      90/10 1000  0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   23 × 10.sup.7                                               100/0 1000  9 × 10.sup.4                                                0/100 25    34 × 10.sup.8                                               0/100 50    17 × 10.sup.6                                               0/100 100   18 × 10.sup.4                                               0/100 200   3 × 10                       Bacillus                                                                             Potassium sorbate                                                                         Dodecyldi(aminoethyl)-                                     subtilis           glycine     95/5  500   8 × 10                                                      95/5  1000  0                                                                 90/10 500   3 × 10                                                      90/10 1000  0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   7 × 10.sup.8                                                100/0 1000  5 × 10.sup.7                                                0/100 25    34 × 10.sup.8                                               0/100 50    17 × 10.sup.6                                               0/100 100   18 × 10.sup.4                                               0/100 200   3 × 10                       Bacillus                                                                             Dehydroacetic acid                                                                        Sodium salt of 2-pyri-                                     subtilis           dinethiol 1-oxide                                                                         95/5  500   2 × 10                                                      95/5  1000  0                                                                 90/10 500   1 × 10                                                      90/10 1000  0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   8 × 10.sup.5                                                100/0 1000  12 × 10.sup.3                                               0/100 25    12 × 10.sup.5                                               0/100 50    20 × 10.sup.3                                               0/100 100   30 × 10.sup.2                                               0/100 200   5 × 10                       Bacillus                                                                             Sorbic acid Sodium salt of 2-pyri-                                     subtilis           dinethiol 1-oxide                                                                         95/5  500   9                                                                 95/5  1000  0                                                                 90/10 500   8                                                                 90/10 1000  0                                                                 80/20 500   5                                                                 80/20 1000  0                                                                 60/40 500   0                                                                 100/0 500   13 × 10.sup.6                                               100/0 1000  18 × 10.sup.4                                               0/100 25    12 × 10.sup.5                                               0/100 50    20 × 10.sup.3                                               0/100 100   30 × 10.sup.2                                               0/100 200   5 × 10                       Escherichia                                                                          Dehydroacetic acid                                                                        Tetrahydro-3,5-di-                                         coli               methyl-2H-1,3,5-thia-                                                                     95/5  500   13                                                    diazine-2-thione                                                                          95/5  1000  0                                                                 90/10 500   0                                                                 90/10 1000  0                                  Escherichia                                                                          Dehydroacetic acid                                                                        Tetrahydro-3,5-di-                                         coli               methyl-2H-1,3,5-thia-                                                                     80/20 500   0                                                     diazine-2-thione                                                                          60/40 500   0                                                                 100/0 500   13 × 10.sup.8                                               100/0 1000  31 × 10.sup.6                                               0/100 25    38 × 10.sup.5                                               0/100 50    6 × 10.sup.3                                                0/100 100   16 × 10.sup.2                                               0/100 200   9 × 10                       Escherichia                                                                          Sorbic acid Tetrahydro-3,5-di-                                         coli               methyl-2H-1,3,5-thia-                                                                     95/5  500   15                                                    diazine-2-thione                                                                          95/5  1000  0                                                                 90/10 500   8                                                                 90/10 1000  0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   8 × 10.sup.6                                                100/0 1000  7 × 10.sup.5                                                0/100 25    38 × 10.sup.5                                               0/100 50    6 × 10.sup.3                                                0/100 100   16 × 10.sup.2                                               0/100 200   9 × 10                       Staphylococ-                                                                         Dehydroacetic acid                                                                        Tetradecyldi(amino-                                        cus aureus         ethyl)glycine                                                                             95/5  500   9 × 10                                                      95/5  1000  0                                                                 90/10 500   4 × 10                                                      90/10 1000  0                                                                 80/20 500   5 × 10                                                      80/20 1000  0                                                                 60/40 500   0                                                                 100/0 500   22 × 10.sup.5                                               100/0 1000  6 × 10.sup.3                                                0/100 25    19 × 10.sup.8                                               0/100 50    17 × 10.sup. 6                                              0/100 100   18 × 10.sup.4                                               0/100 200   7 × 10                       Staphylococ-                                                                         Sorbic acid Tetradecyldi(amino-                                        cus aureus         ethyl)glycine                                                                             95/5  500   15 × 10                                                     95/5  1000  0                                                                 90/10 500   13 × 10                                                     90/10 1000  0                                                                 80/20 500   5 × 10                                                      80/20 1000  0                                                                 60/40 500   0                                                                 100/0 500   21 × 10.sup.6                                               100/0 1000  5 × 10.sup.3                                                0/100 25    19 × 10.sup.8                                               0/100 50    17 × 10.sup.6                                               0/100 100   18 × 10.sup.4                                               0/100 200   7 × 10                       Pseudomonas                                                                          Sodium dehydroacetate                                                                     Sodium salt of 2-pyri-                                     aeruginosa         dinethiol 1-oxide                                                                         95/5  500   9                                                                 95/5  1000  0                                                                 90/10 500   4                                                                 90/10 1000  0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   15 ×  10.sup.8                                              100/0 1000  2 × 10.sup.7                                                0/100 25    3 × 10.sup.6                                                0/100 50    6 × 10.sup.4                                                0/100 100   9 × 10.sup.3                                                0/100 200   4 × 10                       Pseudomonas                                                                          Potassium sorbate                                                                         Sodium salt of 2-pyri-                                     aeruginosa         dinethiol 1-oxide                                                                         95/5  500   11 × 10                                                     95/5  1000  0                                                                 90/10 500   6 × 10                                                      90/10 1000  0                                                                 80/20 500   1 × 10                                                      80/20 1000  0                                                                 60/40 500   0                                                                 100/0 500   15 × 10.sup.10                                              100/0 1000  7 × 10.sup.8                                                0/100 25    3 × 10.sup.6                                                0/100 50    6 × 10.sup.4                                                0/100 100   9 × 10.sup.3                                                0/100 200   4 × 10                       Pseudomonas                                                                          Sodium dehydroacetate                                                                     Tetrahydro-3,5-dimethyl-                                   aeruginosa         2H-1,3,5-thiadiazine-                                                                     95/5  500   3                                                     2-thione    95/5  1000  0                                                                 90/10 500   0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   15 × 10.sup.8                                               100/0 1000  2 × 10.sup.7                                                0/100 25    7 × 10.sup.5                                                0/100 50    38 × 10.sup.3                                               0/100 100   6 × 10.sup.2                                                0/100 200   3 × 10                       Pseudomonas                                                                          Potassium sorbate                                                                         Tetrahydro-3,5-dimethyl-                                   aeruginosa         2H-1,3,5-thiadiazine-                                                                     95/5  500   8                                                     2-thione    95/5  1000  0                                                                 90/10 500   0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   15 × 10.sup.10                                              100/0 1000  7 × 10.sup.8                                                0/100 25    7 × 10.sup.5                                                0/100 50    38 × 10.sup.3                                               0/100 100   6 × 10.sup.2                                                0/100 200   3 × 10                       __________________________________________________________________________

EXAMPLE 2

A 5% aqueous solution of starch was prepared and sterilized, and 100 ml.portions thereof were poured into 200 ml. bottles. After adding aprescribed amount of an antibacterial, antifungal composition consistingof the components (A) and (B) as shown in Table 2 to each bottle andthoroughly agitating, 1 ml. (number of fungi: 5×10⁶ fungi/ml.) of anaqueous suspension of fungi as shown in Table 2 was added to each bottleand was agitated again. The thus prepared aqueous solution contained5×10⁴ fungi per gram. The bottles were then sealed and allowed to standat 30° C. for a week. The state of the growth of fungi was observed bymeasuring the number of fungi in 1 g. of the aqueous solution.

The results are shown in Table 2.

                                      TABLE 2                                     __________________________________________________________________________                                          Amount of                                      Antibacterial, antifungal composition                                                                        composition                                                                         Number of                                                         (A)/(B)                                                                             added fungi                             Fungi  Component (A)                                                                             Component (B)                                                                              by weight                                                                           (p.p.m.)                                                                            (fungi/g.)                        __________________________________________________________________________    Aspergillus                                                                          Sodium dehydroacetate                                                                     Dodecyldi(aminoethyl)-                                     niger              glycine      95/5  500   5                                                                 95/5  1000  0                                                                 90/10 500   3                                                                 90/10 1000  0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   18 × 10.sup.7                                               100/0 1000  30 × 10.sup.4                                               0/100 25    8 × 10.sup.8                                                0/100 50    13 × 10.sup.6                                               0/100 100   28 × 10.sup.5                                               0/100 200   7 × 10.sup.2                Aspergillus                                                                          Potassium sorbate                                                                         Dodecyldi(aminoethyl)-                                     niger              glycine      95/5  500   4 × 10                                                      95/5  1000  0                                                                 90/10 500   2 × 10                                                      90/10 1000  0                                                                 80/20 500   7                                                                 80/20 1000  0                                                                 60/40 500   0                                                                 100/0 500   7 × 10.sup.10                                               100/0 1000  37 × 10.sup.8                                               0/100 25    8 × 10.sup.8                                                0/100 .50   13 × 10.sup.6                                               0/100 100   28 × 10.sup.5                                               0/100 200   7 × 10.sup.2                Aspergillus                                                                          Sodium dehydroacetate                                                                     Sodium salt of 2-pyri-                                     niger              dinethiol 1-oxide                                                                          95/5  500   7                                                                 95/5  1000  0                                                                 90/10 500   0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   18 × 10.sup.7                                               100/0 1000  30 × 10.sup.4                                               0/100 25    28 × 10.sup.4                                               0/100 50    19 × 10.sup.3                                               0/100 100   13 × 10.sup.2                                               0/100 200   4 × 10                      Aspergillus                                                                          Potassium sorbate                                                                         Sodium salt of 2-pyri-                                     niger              dinethiol 1-oxide                                                                          95/5  500   9                                                                 95/5  1000  0                                                                 90/10 500   5                                                                 90/10 1000  0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   7 × 10.sup.10                                               100/0 1000  37 × 10.sup.8                                               0/100 25    28 × 10.sup.4                                               0/100 50    19 × 10.sup.3                                               0/100 100   13 × 10.sup.2                                               0/100 200   5 × 10                      Aspergillus                                                                          Sodium dehydroacetate                                                                     Tetrahydro-3,5-dimethyl-                                   niger              2H-1,3,5-thiadiazine-                                                                      95/5  500   6 × 10                                         2-thione     95/5  1000  0                                                                 90/10 500   5 × 10                                                      90/10 1000  0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   18 × 10.sup.7                                               100/0 1000  30 × 10.sup.4                                               0/100 25    7 × 10.sup.4                                                0/100 50    12 × 10.sup.3                                               0/100 100   19 × 10.sup.2                                               0/100 200   3 × 10                      Aspergillus                                                                          Potassium sorbate                                                                         Tetrahydro-3,5-dimethyl-                                   niger              2H-1,3,5-thiadiazine-                                                                      95/5  500   5 ×  10                                        2-thione     95/5  1000  0                                                                 90/10 500   2 × 10                                                      90/10 1000  0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   7 × 10.sup.7                                                100/0 1000  37 × 10.sup.8                                               0/100 25    7 × 10.sup.4                                                0/100 50    12 × 10.sup.3                                               0/100 100   19 × 10.sup.2                                               0/100 200   3 × 10                      Penicillium                                                                          Dehydroacetic acid                                                                        Tetradecyldi(aminoethyl)-                                  citrinum           glycine      95/5  500   10                                                                95/5  1000  0                                                                 90/10 500   4                                                                 90/10 1000  0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   1 × 10.sup.5                                                100/0 1000  17 × 10.sup.3                                               0/100 25    5 × 10.sup.7                                                0/100 50    8 × 10.sup.5                                                0/100 100   30 × 10.sup.3                                               0/100 200   6 × 10                      Penicillium                                                                          Sorbic acid Tetradecyldi(aminoethyl)-                                  citrinum           glycine      95/5  500   4 × 10                                                      95/5  1000  0                                                                 90/10 500   3 × 10                                                      90/10 1000  0                                                                 80/20 500   3 × 10                                                      80/20 1000  0                                                                 60/40 500   2 × 10                                                      60/40 1000  0                                                                 100/0 500   7 × 10.sup.7                                                100/0 1000  40 × 10.sup.5                                               0/100 25    5 × 10.sup.7                                                0/100 50    8 × 10.sup.5                                                0/100 100   30 × 10.sup.3                                               0/100 200   6 × 10                      Penicillium                                                                          Dehydroacetic acid                                                                        Sodium salt of 2-pyri-                                     citrinum           dinethiol 1-oxide                                                                          95/5  500   2                                                                 95/5  1000  0                                                                 90/10 500   0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   1 × 10.sup.5                                                100/0 1000  17 × 10.sup.3                                               0/100 25    17 × 10.sup.4                                               0/100 50    15 × 10.sup.3                                               0/100 100   8 × 10.sup.2                                                0/100 200   3 × 10                      Penicillium                                                                          Sorbic acid Sodium salt of 2-pyri-                                     citrinum           dinethiol 1-oxide                                                                          95/5  500   5 × 10                                                      95/5  1000  0                                                                 90/10 500   3 × 10                                                      90/10 1000  0                                                                 80/20 500   0                                                                 60/40 500   0                                                                 100/0 500   7 × 10.sup.7                                                100/0 1000  40 × 10.sup.5                                               0/100 25    17 × 10.sup.4                                               0/100 50    15 × 10.sup.3                                               0/100 100   8 × 10.sup.2                                                0/100 200   3 × 10                      Cladosporium                                                                         Dehydroacetic acid                                                                        Tetrahydro-3,5-dimethyl-                                   resinae            2H-1,3,5-thiadiazine-                                                                      95/5  100   8 × 10                                         2-thione     95/5  500   0                                                                 90/10 100   5 × 10                                                      90/10 500   0                                                                 80/20 100   9                                                                 80/20 500   0                                                                 60/40 100   0                                                                 100/0 100   15 × 10.sup.7                                               100/0 500   10 × 10.sup.5                                               0/100 5     27 × 10.sup.5                                               0/100 25    11 × 10.sup.3                                               0/100 50    11 × 10.sup.2                                               0/100 100   9 × 10                      Cladosporium                                                                         Sorbic acid Tetrahydro-3,5-dimethyl-                                   resinae            2H-1,3,5-thiadiazine-                                                                      95/5  100   7 × 10                                         2-thione     95/5  500   2                                                                 90/10 100   6                                                                 80/20 500   0                                                                 80/20 100   0                                                                 60/40 100   0                                                                 100/0 100   9 × 10.sup.7                                                100/0 500   15 × 10.sup.6                                               0/100 5     27 × 10.sup.5                                               0/100 25    11 × 10.sup.3                                               0/100 50    11 × 10.sup.2                                               0/100 100   9 × 10                      __________________________________________________________________________

EXAMPLE 3

A 10% aqueous solution of a polyvinyl alcohol sizing agent was preparedand divided into three portions. To the first portion was added nomedicine, to the second portion was added 2,000 p.p.m. of sodiumdehydroacetate, and to the third portion were added 1,000 p.p.m. ofsodium dehydroacetate and 100 p.p.m. of dodecyldi(aminoethyl)glycine.Epicoccum sp. was inoculated to each of three portions, and they wereallowed to stand in an incubator at 30° C. for 14 days.

In the first and second portions, development of fungi was observedafter 3 and 5 days, respectively, but in the third portion nodevelopment of fungi was observed.

EXAMPLE 4

The procedure of Example 3 was repeated except that potassium sorbatewas employed instead of sodium dehydroacetate.

In the first and second portions, development of fungi was observedafter 4 and 6 days, respectively, but in the third portion nodevelopment of fungi was observed.

EXAMPLE 5

The procedure of Example 3 was repeated except thattetradecyldi(aminoethyl)glycine was employed instead ofdodecyldi(aminoethyl)glycine.

In the first and second portions, development of fungi was observedafter 3 and 5 days, respectively, but in the third portions nodevelopment of fungi was observed.

EXAMPLE 6

An antibacterial, antifungal composition was prepared by admixing 95 g.of sodium dehydroacetate and 5 g. of dodecyldi(aminoethyl)glycine. Thecomposition was added to a 18% solution of a crotonic acid-vinyl acetatecopolymer in a concentration of 2,500 p.p.m., 5,000 p.p.m. or 7,500p.p.m., respectively.

Each of the thus prepared three coating solutions was sprayed onto twosides of a fancy mat (10×10 cm.) in an amount of 2 g. of on each side,and was then dried at 140° C. for 2 minutes.

The coated fancy mats were allowed to stand under a saturated humidityat 25° C., and the state of the growth of fungi was observed with thelapse of time.

The results are shown in Table 3, in which symbols are as follows:

-: No growth

±: A little growth

+: Growth (The more the number of the symbol +, the larger the growth.)

                                      TABLE 3                                     __________________________________________________________________________    Amount of                                                                     composition                                                                          Incubation days                                                        (p.p.m.)                                                                             5 6 7  8   10   12     14                                              __________________________________________________________________________    0      --                                                                              + ++ +++ ++++ +++++  +++++                                           2,500  --                                                                              --                                                                              +  +   +++  +++    ++++                                            5,000  --                                                                              --                                                                              -- ±                                                                              +    ++     +++                                             7,500  --                                                                              --                                                                              -- --  --   --     --                                              __________________________________________________________________________

EXAMPLE 7

A sizing solution containing 5% of wheat starch and a sizing solutioncontaining 5% of casein were prepared, and thereto was added a medicineas shown in Table 4. After adding a suspension of fungi consisting ofAspergillus niger, Penicillium citrinum, Cladosporium herbaum andChaetomium globorum to each of the sizing solutions, the sizingsolutions were placed in an incubator at 28° C. and the state of thegrowth of fungi was observed.

The results are shown in Table 4, in which symbols are as follows:

-: No growth

±: A little growth

+: Growth (The more the number of the symbol +, the larger the growth.)

                                      TABLE 4                                     __________________________________________________________________________    Sizing          Incubation days                                               solution                                                                             Medicine 0 4 7   14   21   28                                          __________________________________________________________________________    Wheat starch                                                                         None     --                                                                              + +++ ++++ ++++ ++++                                        Casein "        --                                                                              --                                                                              ++  +++  ++++ ++++                                               Sodium dehydro-                                                        Wheat starch                                                                         acetate (500                                                                           --                                                                              --                                                                              ±                                                                              ++   +++  +++                                                p.p.m.)                                                                Casein "        --                                                                              --                                                                              --  ± ++   +++                                                Sodium dehydro-                                                        Wheat starch                                                                         acetate (475                                                                           --                                                                              --                                                                              --  --   --   --                                                 p.p.m.) and                                                                   dodecyldi (amino-                                                             ethyl) glycine                                                                (25 p.p.m.)                                                            Casein "        --                                                                              --                                                                              --  --   --   --                                          __________________________________________________________________________

EXAMPLE 8

A 10% aqueous solution of a polyvinyl alcohol sizing agent was preparedand divided into three portions. To the first portion was added nomedicine, to the second portion was added 1,000 p.p.m. of sodiumdehydroacetate, and to the third portion were added 250 p.p.m. of sodiumdehydroacetate and 10 p.p.m. of sodium salt of 2-pyridinethiol 1-oxide.An aqueous suspension of fungi consisting of Epicoccum sp.,Cephalosporium sp. and Fusarium oxysporium was added to each of threeportions in an amount of 0.3 ml. to 100 g. of the 10% aqueous solutionof the sizing agent, and they were then allowed to stand in an incubatorat 30° C. for 14 days.

In the first and second portions, development of fungi was observedafter 2 and 5 days, respectively, but in the third portion nodevelopment of fungi was observed.

EXAMPLE 9

The procedure of Example 8 was repeated except that sodium sorbate wasemployed instead of sodium dehydroacetate.

In the first and second portions, development of fungi was observedafter 3 and 5 days, respectively, but in the third portion nodevelopment of fungi was observed.

EXAMPLE 10

Three samples were prepared by admixing 8 ml. of water with each ofsample A (5 g. of a mosquito-repellent incense powder containing nomedicine), sample B (5 g. of a mosquito-repellent incense powdercontaining 500 p.p.m. of sodium dehydroacetate) and sample C (5 g. of amosquito-repellent incense powder containing 250 p.p.m. of sodiumdehydroacetate and 10 p.p.m. of sodium salt of 2-pyridinethiol 1-oxide)and then molding the resulting mixture into a disc having a radius of 5cm. and a thickness of 0.5 cm. To each sample was added 0.3 ml. of anaqueous suspension of fungi consisting of Aspergillus niger, Penicilliumluteum, Cladosporium herbaum, Pullularia pullulans and Fusariumoxyporium.

The samples were allowed to stand at a temperature of 28° C. and ahumidity of 90% for two weeks, and the state of the development of fungiwas then observed.

In sample A and sample B, development of fungi was observed after 2 and5 days, respectively, but in sample C no development of fungi wasobserved.

EXAMPLE 11

To a polyvinyl acetate emulsion (solid content: 10%) was added 2% ofagar, and by employing this emulsion the following three samples wereprepared; sample A: emulsion containing no medicine, sample B: emulsioncontaining 1,000 p.p.m. of sodium dehydroacetate, and sample C: emulsioncontaining 250 p.p.m. of sodium dehydroacetate and 10 p.p.m. of sodiumsalt of 2-pyridinethiol 1-oxide.

An aqueous suspension of fungi of Aspergillus niger was added dropwiseto each sample, and was cultured in an incubator at 28° C.

In sample A and sample B, development of fungi was observed after 2 and5 days, respectively, but in sample C no development of fungi wasobserved even after a week.

EXAMPLE 12

By employing a sizing solution containing 5% of wheat starch, thefollowing three samples were prepared; sample A: sizing solutioncontaining no medicine, sample B: sizing solution containing 500 p.p.m.of sodium dehydroacetate, and sample C: sizing solution containing 100p.p.m. of sodium dehydroacetate and 50 p.p.m. of 2-pyridinethiol1-oxide. An aqueous suspension of fungi consisting of Aspergillus niger,Penicillium citrinum, Cladosporium herbaum and Chaetomium globosum wasinoculated into each sample, and the state of the development of fungiwas observed in an incubator at 28° C.

In sample A and sample B, development of fungi was observed after 2 and4 days, respectively, but in sample C no development of fungi wasobserved even after 21 days.

EXAMPLE 13

By employing a wall covering material for decorative use (commerciallyavailable under the tradename "Orion Coat kabe" made by Umehiko Co.),the following three samples were prepared; sample A: wall coveringmaterial containing no medicine, sample B: wall covering materialcontaining 0.1% of sodium dehydroacetate, and sample C: wall coveringmaterial containing 0.09% of sodium dehydroacetate and 0.01% of sodiumsalt of 2-pyridinethiol 1-oxide. Each sample was thoroughly admixed withwater and was coated thin on a veneer. After air-dry for 2 days, thecoated veneers were cut into pieces of 5 cm.×5 cm. and the coatings werethen peeled off.

A drop of an aqueous suspension of Aspergillus niger was dropped on eachcoating, and the state of the development of fungi was observed at atemperature of 28° C. and a humidity of 91%.

In sample A and sample B, development of fungi was observed after 2 and3 days, respectively, but in sample C no development of fungi wasobserved after the lapse of at least a week.

EXAMPLE 14

To 99 g. of a water base putty were added an antibacterial, antifungalcomposition consisting of the components (A) and (B) as shown in Table 5and 1 ml. of an aqueous suspension of bacteria and fungi (bacteria:Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis andStaphylococcus aureus, fungi: Aspergillus niger, Aspergillus oryzae,Cladosporium resinae, Cheatomium globosum and Penicillium citrinum), andthey were thoroughly admixed. The thus prepared sample containedbacteria of 15×10⁶ cells/g. and fungi of 6×10⁵ cells/g.

The sample was placed in a bottle, and after sealing the bottle, thebottle was placed in an incubator at 30° C. and the state of the growthof microorganisms was observed with the lapse of time. The state of thegrowth was evaluated by measuring the number of bacteria and fungi in 1g. of the sample.

The results are shown in Table 5.

                                      TABLE 5                                     __________________________________________________________________________                           Content of                                             Antibacterial, antifungal composition                                                                composition                                                                         Number of microorganism (cells/g.)                                (A)/(B)                                                                             in sample                                                                           After 10 days                                                                          After 30 days                           Component (A)                                                                          Component (B)                                                                         by weight                                                                           (%)   Bacteria                                                                           Fungi                                                                             Bacteria                                                                           Fungi                              __________________________________________________________________________    Potassium                                                                              Tetrahydro-3,5-                                                      sorbate  dimethyl-2H-                                                                          95/5  0.02  13 × 10.sup.2                                                                0   7 × 10.sup.2                                                                 0                                           1,3,5-thiadi-                                                                         95/5  0.05  0    0   0    0                                           azine-2-thione                                                                        80/20 0.02  10 × 10.sup.2                                                                0   3 × 10.sup.2                                                                 0                                                   80/20 0.05  0    0   0    0                                                   100/0 0.05  25 × 10.sup.6                                                                9 × 10.sup.5                                                                18 × 10.sup.8                                                                11 × 10.sup.7                                 0/100 0.01  16 × 10.sup.4                                                                3 × 10.sup.5                                                                34 × 10.sup.4                                                                5 × 10.sup.5                 Sodium dehydro-                                                                        Tetrahydro-3,5-                                                      acetate  dimethyl-2H-                                                                          95/5  0.02  14 × 10.sup.2                                                                0   5 × 10.sup.2                                                                 0                                           1,3,5-thiadi-                                                                         95/5  0.05  0    0   0    0                                           azine-2-thione                                                                        80/20 0.02  8 × 10.sup.2                                                                 0   0    0                                                   80/20 0.05  0    0   0    0                                                   100/0 0.05  18 × 10.sup.6                                                                12 × 10.sup.4                                                               27 × 10.sup.8                                                                13 × 10.sup.4                                 0/100 0.01  16 × 10.sup.4                                                                3 × 10.sup.5                                                                34 × 10.sup.4                                                                5 × 10.sup.5                 Sorbic acid                                                                            Tetrahdyro-3,5-                                                               dimethyl-2H-                                                                          95/5  0.02  13 × 10.sup.2                                                                0   6 × 10.sup.2                                                                 0                                           1,3,5-thiadi-                                                                         95/5  0.05  0    0   0    0                                           azine-2-thione                                                                        80/20 0.02  9 × 10.sup.2                                                                 0   2 × 10.sup.2                                                                 0                                                   80/20 0.05  0    0   0    0                                                   100/0 0.05  23 × 10.sup.6                                                                15 × 10.sup.5                                                               8 × 10.sup.8                                                                 22 × 10.sup.7                                 0/100 0.01  16 × 10.sup.4                                                                3 × 10.sup.5                                                                34 × 10.sup.4                                                                5 × 10.sup.5                 Dehydroacetic                                                                          Tetrahdyro-3,5-                                                      acid     diemthyl-2H-                                                                          95/5  0.02  3 × 10.sup.2                                                                 0   3 × 10.sup.2                                                                 0                                           1,3,5-thiadi-                                                                         95/5  0.05  0    0   0    0                                           azine-2-thione                                                                        80/20 0.02  2 × 10.sup.2                                                                 0   0    0                                                   80/20 0.05  0    0   0    0                                                   100/0 0.05  15 × 10.sup.6                                                                7 × 10.sup.4                                                                14 × 10.sup.8                                                                7 × 10.sup.4                                  0/100 0.01  16 × 10.sup.4                                                                3 × 10.sup.5                                                                34 × 10.sup.4                                                                5 × 10.sup.5                 --       --      --    0     12 × 10.sup.8                                                                >10.sup.10                                                                        25 × 10.sup.8                                                                >10.sup.10                         __________________________________________________________________________

EXAMPLE 15

The procedures of Example 14 were repeated except a polyvinyl acetateemulsion was employed instead of the putty and a sample emulsioncontaining bacteria of 25×10⁵ cells/g. and fungi of 13×10⁵ cells/g. wasprepared.

The results are shown in Table 6.

                                      TABLE 6                                     __________________________________________________________________________                        Content                                                                       of com-                                                   Antibacterial, antifungal composition                                                             position                                                                           Number of microorganism (cells/g.)                                  (A)/(B)                                                                            in emul-                                                                           After 1 month                                                                          After 2 months                                                                         After 3 months                     Component (A)                                                                        Composition (B)                                                                       by wt.                                                                             sion (%)                                                                           Bacteria                                                                           Fungi                                                                             Bacteria                                                                           Fungi                                                                             Bacteria                                                                           Fungi                         __________________________________________________________________________    Potassium                                                                            Tetrahydro-3,5-                                                        sorbate                                                                              dimethyl-2H-                                                                          95/5 0.05 3 × 10.sup.2                                                                 3 × 10.sup.2                                                                0    0   0    0                                    1,3,5-thiadi-                                                                         95/5 0.1  2 × 10.sup.2                                                                 0   0    0   0    0                                    azine-2-thione                                                                        80/20                                                                              0.05 4 × 10.sup.2                                                                 5 × 10.sup.2                                                                0    0   0    0                                            80/20                                                                              0.1  3 × 10.sup.2                                                                 0   0    0   0    0                                            100/0                                                                              0.1  23 × 10.sup.5                                                                9 × 10.sup.5                                                                18 × 10.sup.7                                                                8 × 10.sup.8                                                                15 × 10.sup.8                                                                >10.sup.10                                   0/100                                                                              0.02 18 × 10.sup.4                                                                21 × 10.sup.4                                                               6 × 10.sup.5                                                                 31 × 10.sup.4                                                               5 × 10.sup.5                                                                 26 × 10.sup.4           Sodium dehy-                                                                         Tetrahydro-3,5-                                                        droacetate                                                                           dimethyl-2H-                                                                          95/5 0.05 18 × 10.sup.2                                                                21 × 10.sup.2                                                               2 × 10.sup.2                                                                 3 × 10.sup.2                                                                0    0                                    1,3,5-thiadi-                                                                         95/5 0.1  2 × 10.sup.2                                                                 2 × 10.sup.2                                                                0    0   0    0                                    azine-2-thione                                                                        80/20                                                                              0.05 4 × 10.sup.2                                                                 0   0    0   0    0                                            80/20                                                                              0.1  3 × 10.sup.2                                                                 0   0    0   0    0                                            100/0                                                                              0.1  14 × 10.sup.5                                                                5 × 10.sup.4                                                                9 × 10.sup.6                                                                 13 × 10.sup.4                                                               32 × 10.sup.8                                                                >10.sup.10                                   0/100                                                                              0.2  18 × 10.sup.4                                                                21 × 10.sup.4                                                               6 × 10.sup.5                                                                 31 × 10.sup.4                                                               5 × 10.sup.5                                                                 26 × 10.sup.4           Sorbic acid                                                                          Tetrahydro-3,5-                                                               dimethyl-2H-                                                                          95/5 0.05 2 × 10.sup.2                                                                 0   0    0   0    0                                    1,3,5-thiadi-                                                                         95/5 0.1  1 × 10.sup.2                                                                 0   0    0   0    0                                    azine-2-thione                                                                        80/20                                                                              0.05 11 × 10.sup.2                                                                0   0    0   0    0                                            80/20                                                                              0.1  7 × 10.sup.2                                                                 0   0    0   0    0                                            100/0                                                                              0.1  18 × 10.sup.5                                                                5 × 10.sup.5                                                                15 × 10.sup.7                                                                >10.sup.10                                                                        9 × 10.sup.8                                                                 >10.sup.10                                   0/100                                                                              0.02 18 × 10.sup.4                                                                21 × 10.sup.4                                                               6 × 10.sup.5                                                                 31 × 10.sup.4                                                               5 × 10.sup.5                                                                 26 × 10.sup.4           Dehydro-                                                                             Tetrahydro-3,5-                                                        acetic adic                                                                          dimethyl-2H-                                                                          95/5 0.05 6 × 10.sup.2                                                                 1 × 10.sup.2                                                                0    0   0    0                                    1,3,5-thiadi-                                                                         95/5 0.1  5 × 10.sup.2                                                                 0   0    0   0    0                                    azine-2-thione                                                                        80/20                                                                              0.05 2 × 10.sup.2                                                                 2 × 10.sup.2                                                                0    0   0    0                                            80/20                                                                              0.1  2 × 10.sup.2                                                                 0   0    0   0    0                                            100/0                                                                              0.1  14 × 10.sup.5                                                                3 × 10.sup.4                                                                16 × 10.sup.6                                                                13 × 10.sup.5                                                               21 × 10.sup.8                                                                >10.sup.10                                   0/100                                                                              0.02 18 × 10.sup.4                                                                21 × 10.sup.4                                                               6 × 10.sup.5                                                                 31 ×  10.sup.4                                                              5 × 10.sup.5                                                                 26 × 10.sup.4           --     --      --   0    33 × 10.sup.6                                                                19 × 10.sup.6                                                               19 × 10.sup.8                                                                >10.sup.10                                                                        20 × 10.sup.8                                                                >10.sup.10                    __________________________________________________________________________

What we claim is:
 1. An antibacterial and antifungal compositioncomprising a mixture of:(A) at least one member selected from the groupconsisting of dehydroacetic acid, and its alkali metal salts, whereinsaid member is contained within said composition in an amount from60%-95% by weight, based on the total weight of the composition, and (B)tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione in asynergistically effective amount of 0.5% to 40% by weight based on theweight of the total composition.
 2. An antibacterial and antifungalcomposition as in claim 1, wherein saidtetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione is containedwithin said composition in an amount of from 5 to 40% by weight based onthe total weight of the composition.